The disclosure relates generally to gear pumps, and more specifically, to gear pumps with reduced cavitation.
Though gear pumps are considered highly reliable, in some aircraft engine applications, incorrectly or inconsistently pressurized fuel or oil can seriously affect engine system performance and reduce component life. For example, vapor pockets or bubbles are seen under certain flow or operating conditions of conventional gear pumps. Under certain operating conditions, two-phase flow occurs. If left alone, vapor pockets can collapse from flashback into liquid phase, thus resulting in unwanted flow cavitation of liquid converging into spaces between rapidly unmeshing gear teeth. This is noisy, creating pressure waves, which more quickly erode the gear teeth, increasing repair costs and frequency.
In the short term, erosion products from cavitation bubbles' flashback can also contaminate the fluid being pumped, requiring additional filtration to prevent component damage and/or pollution. In the longer term, filters need to be changed more frequently, and the pumping efficiency of the gear pump is reduced due to uneven flow surfaces, necessitating replacement or repair.